Accounts Payable and Accrued Liabilities - Summary of Components of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accounts payable	$ 11,645	$ 9,397
Accrued price adjustments	3,036	592
Accrued returns	857
Accrued acquisition consideration	4,838
Accrued rebates	5,057	3,842
Accrued chargebacks	101	10
Accrued compensation and benefits	3,067	2,052
Accrued royalties	488	518
Accrued clinical trial costs	7	615
Accrued legal costs	562	490
Accrued manufacturing costs	200	200
Accrued sales and marketing costs		193
Accrued other	949	265
Total accounts payable and accrued expenses	$ 30,807	$ 18,174